enhance formatters

weboob/tools/application/formatters/iformatter.py

@@ -0,0 +1,70 @@
+# -*- coding: utf-8 -*-
+
+# Copyright(C) 2010  Christophe Benz
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 3 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+
+import types
+
+
+__all__ = ['IFormatter']
+
+
+class IFormatter(object):
+    def format(self, obj, selected_fields=None, condition=None):
+        """
+        Format an object to be human-readable.
+        An object has fields which can be selected, and the objects
+        can be filtered using a condition (like SELECT and WHERE in SQL).
+        If the object provides an iter_fields() method, the formatter will
+        call it. It can be used to specify the fields order.
+
+        @param obj  [object] object to format
+        @param selected_fields  [list] fields to display
+        @param condition  [Condition] condition to objects to display 
+        @return  a string of the formatted object
+        """
+        item = self.to_dict(obj, condition)
+        if selected_fields is None:
+            selected_fields = sorted(item)
+        return self.format_dict(item=item, selected_fields=selected_fields)
+
+    def format_dict(self, item, selected_fields):
+        """
+        Format an dict to be human-readable.
+        Called by format().
+        This method has to be overridden in child classes.
+
+        @param item  [dict] item to format
+        @param selected_fields  [list] fields to display
+        @return  a string of the formatted dict
+        """
+        raise NotImplementedError()
+
+    def iter_fields(self, obj):
+        for attribute_name in dir(obj):
+            if attribute_name.startswith('_'):
+                continue
+            attribute = getattr(obj, attribute_name)
+            if not isinstance(attribute, types.MethodType):
+                yield attribute_name, attribute
+
+    def to_dict(self, obj, condition=None):
+        fields_iterator = obj.iter_fields() if hasattr(obj, 'iter_fields') else self.iter_fields(obj)
+        d = dict((k, v) for k, v in fields_iterator)
+        if condition is not None:
+            if not condition.is_valid(d):
+                d = None
+        return d